1. Field of the Invention
The present invention relates to a data reproduction apparatus for successively reproducing a plurality of scene files composing stored data (including at least sound, still photographs, and texts) as per user's manipulation.
2. Description of the Related Art
Data reproduction apparatuses that reproduce digital data as per user's manipulation use a CD-ROM (Compact Disc Read Only Memory) as a data storage medium, which can store a broad range of media including sound, still photographs, moving pictures, texts, characters, program data, etc. Accordingly, applications such that handle the media stored in the CD-ROM as integrated data, or so-called multi-media applications, have been developed and are in practical use in the field of entertainment, presentation, and electronic books.
An electronic book application, one of the multi-media applications, has the same structure as a book in terms of the articles or the table of contents to reproduce books electronically from the digital data including at least three elements: sound, still photographs, and texts. Unlike a music application that reproduces stored data successively through a single channel (no branch channels exit in this application), the electronic application reproduces articles, which are the minimum units of data for reproduction, through a number of channels by means of an electronic book player (data reproduction apparatus). More precisely, the channels are selected by the user where the selection is possible, for example at the table of contents, and the data are reproduced through the selected channels.
The selection of the reproduction channel with the electronic book player will be explained with reference to FIG. 1, which schematically shows stored data having a plurality of reproduction channels (branches).
Once the reproduction operation starts, a scene file Y1 is reproduced first, and then a scene file Y2. Since scene files Y3, Y7, and Y10 are branched from the scene file Y2, the electronic book player waits for a branch command from the user to resume the reproduction of a specified scene file through branching. For example, when the scene file Y7 is specified, the scene files Y7, Y8, Y5 and Y6 are successively reproduced subsequent to the scene file Y2.
As the electronic book players have been used widely, there has been an increasing need for a technique to reproduce the secondary data while the primary data (scene files) are being reproduced; the secondary data referred herein are, for example, advertisement data, which are not directly related to the primary data.
Conventionally, the advertisement data are inserted into the scene files to be reproduced as an integral part thereof. For example, scene files Y4 and Y8 are advertisement data and inserted after scene files Y3 and Y7, respectively.
This means that the advertisement data are reproduced only when the user selects the reproduction channels including the advertisement data among a plurality of reproduction channels, and reproduction process has achieved at individual advertisement data. However, some reproduction channels are frequently reproduced and some are not depending on the user, making it difficult to ensure the same reproduction frequency for individual advertisement data.
For example, assume that the chances for the scene files Y3, Y7, and Y10 to be selected after the scene file Y2 are 1/7, 2/7, and 4/7 respectively, then the chances for the scene files Y4 and Y8 to be reproduced are 1/7 and 2/7 respectively.
Such irregular chances raise the problem of the advertisement rates: the advertisement rates can be set easily for paper media (magazines), but not for the electronic book application. To be more specific, paper media (magazines) contains various kinds of advertisements, and the advertisement rates generally vary depending on their location. Although the more frequently or less frequently turned pages depends on the reader, the reader generally turns the pages from front to back, and thus the publisher and advertiser can specify the most frequently turned pages relatively easy. Thus, the advertisement rates are directly proportional to pages' frequency to be turned: the rates are high if the advertisement is printed on more frequently turned pages such as the first page of the magazine, and low if printed on less frequently turned pages such as the pages around the middle.
In case of the electronic book application, however, having a plurality of reproduction channels makes it difficult to specify more frequently turned pages, and hence to set the rates. For this reason, neither the publisher nor the advertiser benefits as they do with the magazines by inserting the advertisements in the electronic book application.